Cc Skill Coding Standards

# Coding Standards & Best Practices

Universal coding standards applicable across all projects.

## Code Quality Principles

### 1. Readability First
- Code is read more than written
- Clear variable and function names
- Self-documenting code preferred over comments
- Consistent formatting

### 2. KISS (Keep It Simple, Stupid)
- Simplest solution that works
- Avoid over-engineering
- No premature optimization
- Easy to understand > clever code

### 3. DRY (Don't Repeat Yourself)
- Extract common logic into functions
- Create reusable components
- Share utilities across modules
- Avoid copy-paste programming

### 4. YAGNI (You Aren't Gonna Need It)
- Don't build features before they're needed
- Avoid speculative generality
- Add complexity only when required
- Start simple, refactor when needed

## TypeScript/JavaScript Standards

### Variable Naming

```typescript
// ✅ GOOD: Descriptive names
const marketSearchQuery = 'election'
const isUserAuthenticated = true
const totalRevenue = 1000

// ❌ BAD: Unclear names
const q = 'election'
const flag = true
const x = 1000
```

### Function Naming

```typescript
// ✅ GOOD: Verb-noun pattern
async function fetchMarketData(marketId: string) { }
function calculateSimilarity(a: number[], b: number[]) { }
function isValidEmail(email: string): boolean { }

// ❌ BAD: Unclear or noun-only
async function market(id: string) { }
function similarity(a, b) { }
function email(e) { }
```

### Immutability Pattern (CRITICAL)

```typescript
// ✅ ALWAYS use spread operator
const updatedUser = {
  ...user,
  name: 'New Name'
}

const updatedArray = [...items, newItem]

// ❌ NEVER mutate directly
user.name = 'New Name'  // BAD
items.push(newItem)     // BAD
```

### Error Handling

```typescript
// ✅ GOOD: Comprehensive error handling
async function fetchData(url: string) {
  try {
    const response = await fetch(url)

    if (!response.ok) {
      throw new Error(`HTTP ${response.status}: ${response.statusText}`)
    }

    return await response.json()
  } catch (error) {
    console.error('Fetch failed:', error)
    throw new Error('Failed to fetch data')
  }
}

// ❌ BAD: No error handling
async function fetchData(url) {
  const response = await fetch(url)
  return response.json()
}
```

### Async/Await Best Practices

```typescript
// ✅ GOOD: Parallel execution when possible
const [users, markets, stats] = await Promise.all([
  fetchUsers(),
  fetchMarkets(),
  fetchStats()
])

// ❌ BAD: Sequential when unnecessary
const users = await fetchUsers()
const markets = await fetchMarkets()
const stats = await fetchStats()
```

### Type Safety

```typescript
// ✅ GOOD: Proper types
interface Market {
  id: string
  name: string
  status: 'active' | 'resolved' | 'closed'
  created_at: Date
}

function getMarket(id: string): Promise<Market> {
  // Implementation
}

// ❌ BAD: Using 'any'
function getMarket(id: any): Promise<any> {
  // Implementation
}
```

## React Best Practices

### Component Structure

```typescript
// ✅ GOOD: Functional component with types
interface ButtonProps {
  children: React.ReactNode
  onClick: () => void
  disabled?: boolean
  variant?: 'primary' | 'secondary'
}

export function Button({
  children,
  onClick,
  disabled = false,
  variant = 'primary'
}: ButtonProps) {
  return (
    <button
      onClick={onClick}
      disabled={disabled}
      className={`btn btn-${variant}`}
    >
      {children}
    </button>
  )
}

// ❌ BAD: No types, unclear structure
export function Button(props) {
  return <button onClick={props.onClick}>{props.children}</button>
}
```

### Custom Hooks

```typescript
// ✅ GOOD: Reusable custom hook
export function useDebounce<T>(value: T, delay: number): T {
  const [debouncedValue, setDebouncedValue] = useState<T>(value)

  us